using S turns....to reduce altitude?

classicrock said:
S turns are a maneuver( I have practiced with my CFI) that I thought were to better adjust to or build skill with turning into or away from wind.

until this last week

coming in on final approach, the VASI lights indicated we were too high. my instructor told me to initiate a narrow S Turn immediately(while descending). so I did. (there were very little wind conditions)

it WORKED beautifully.got us right on glide slope.

it would have never occurred to me to do that.

any other pilots done an S turn...on final?
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Yep, and if you make them tight you can scrub off airspeed as well.
 
Unless you have a glass bottom airplane, doing S-turns on final will mean you loose site of the runway. I'll stick with a slip if I miscalculated the descent.
 
cgrab said:
Unless you have a glass bottom airplane, doing S-turns on final will mean you loose site of the runway. I'll stick with a slip if I miscalculated the descent.
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You can lose sight of it, I promise they won't move it or take it away, it will still be right there where t was. Any radial engined tail dragger you don't see the runway for the entire flare and landing if you three point.:lol: What S turns do toss in as a benefit though, especially at uncontrolled airports, is a last scan for traffic coming in on a non standard approach.
 
I've used S-turns to lose altitude on final exactly once in 30 years and happened to be filming when I did it:

https://youtu.be/TZRVs4iEyU8?t=635

The reason I chose S-turns is because my speed brakes were inop and it's not recommended to slip long-body Mooneys.
 
I always teach slips to students but also expose them to S turns. I enjoy slips and showing students it's the same thing landing in a crosswind, to a degree, unless you're flying a B52.

I was based and flew out of ATL for 24 years and it was common to use S turns on final for spacing.
 
It's debatable whether a slip is objectively "safer" than a simple series of S turns - for a student pilot. There are multiple situational "ifs" involved.

But yeah it works because it increases your total distance flown, and thus also time flown, to cover the same straight-line distance to the threshold. If you're descending at a constant rate, more time in the descent means more feet descended.

In another sense, you're making your final approach course longer instead of making your descent angle steeper.
 
Approaching an airport - yes. On final - no.
 
colojo said:
I've used S-turns to lose altitude on final exactly once in 30 years and happened to be filming when I did it:



https://youtu.be/TZRVs4iEyU8?t=635



The reason I chose S-turns is because my speed brakes were inop and it's not recommended to slip long-body Mooneys.
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Your stall horn was on before you flared, is this normal? I'm assuming you were not really going that slow on final.
 
teejayevans said:
Your stall horn was on before you flared, is this normal? I'm assuming you were not really going that slow on final.
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Mine typically is because typically the stall horn comes on 5-10kts above stall, and if you figure a 45kt stall speed has a 1.1 Vso speed of 49.5kts the stall, and 1.1-1.2 Vso is my target speed over the fence, I expect the stall horn to be chirping coming over the fence.
 
An S turn works well for spacing issues and tower will often ask for them. Usually you're on the glide slope when you do them so the thing to remember is to shallow your descent rate while doing the S turn to stay on glide.

So it stands to reason that if you're high you could do the same thing and keep the descent rate to get back on glide slope.

Slips are out in a swept wing aircraft and honestly, I don't do them with pax even with a straight wing. S turns are not ideal either but they're easier to explain than a slip. I just tell them the spacing was too tight and the S turn avoided a missed approach. Since that saves them .2 or .3 they usually say "thank you".
 
Henning said:
Mine typically is because typically the stall horn comes on 5-10kts above stall, and if you figure a 45kt stall speed has a 1.1 Vso speed of 49.5kts the stall, and 1.1-1.2 Vso is my target speed over the fence, I expect the stall horn to be chirping coming over the fence.
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Mine is just above stall speed, 5 at most, add a touch of wind shear and if I tried that (1.1Vso) I would be on the 6 o'clock news.


Sent from my iPhone using Tapatalk
 
teejayevans said:
Mine is just above stall speed, 5 at most, add a touch of wind shear and if I tried that (1.1Vso) I would be on the 6 o'clock news.


Sent from my iPhone using Tapatalk
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Just keep your hand on the throttle and give it a little boost if your ass starts sinking. Remember that your stall speed decreases as you enter ground effect.
 
colojo said:
What Henning said. Also, it was a bit gusty that day so that might have contributed.
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Maybe the video is deceiving but it look like it was going off at 50', the only time I want to hear the stall horn in a Mooney is when I'm in the flare.
 
teejayevans said:
Maybe the video is deceiving but it look like it was going off at 50', the only time I want to hear the stall horn in a Mooney is when I'm in the flare.
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If it's gusty, I may hear chirping all the way down. In fact, it's kinda nice because it allows me to carry more power since I'm on the back side which gives me more prop wash and airflow across the tail which gives me greater ability in a cross wind, plus I am at a much lesser risk of having the throttle not answer a demand for power from 1500-1600rpm than coming up from idle.

There are two ways to fly an approach, power on and power off, and the techniques of the two don't cross over well. If you are going to do a power on approach, do it to your greatest advantage with maximum drag and medium to high power. Power is the easiest of the three energies to manage precisely and dynamically in gusty winds. Both altitude and airspeed have significant adjustment lag and lead times, while power on a recip is near instant.
 
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teejayevans said:
Maybe the video is deceiving but it look like it was going off at 50', the only time I want to hear the stall horn in a Mooney is when I'm in the flare.
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All this talk about the stall horn reminds me that when I bought the plane the stall warning tab was real loosey-goosey and had to be rebuilt during one my annuals. Compare with this landing I made after the repair.

The Acclaim is very nose heavy and drops like a rock if you're too slow so I carry plenty of airspeed cushion into my flare.
 
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Every DA-40 I have flown I had to modify the opening of the stall horn aperture with a strip of medical tape. They typically would be going off at 12-15 kts above stall. Covering the top approximately 1/3rd of the hole with 2 layers of medical tape tuned them down to about 5-7kts above stall. Otherwise they would drive me nuts on final screaming the whole time rather than chirping and buzzing.
 
"S" turns on approach used to be a standard procedure before flaps became common.
I'm a little surprised at how few CFIs teach the technique these days.
 
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